The Aladin name has been one of the biggest
on the dive computer market for several years. The series of computers
manufactured by the Swiss firm Uwatec remains one of the leaders,
even as other major manufacturers have been catching up with their
own models as the use of computers becomes the norm.

The Pro is the company’s decompression computer designed
for air diving. I used it as a back-up to an Aladin Air computer,
which is air-integrated, for a week’s planned decompression
diving in Gibraltar. It has an uncluttered LCD screen, and numerals
and icons are presented boldly. I have rotten eyesight and a low
tolerance level for nitrogen narcosis, so I’m easy to confuse
– working out my exact decompression status can take me a
while with some computers. The Pro presents need-to-know information
in an unambiguous way, and it is extremely easy to assimilate.

The computer automatically switches from sleep to dive mode when you
hit the water, so there’s no chance of a start-up error. If
you dive and still have saturation time left, it will continue to
monitor your altitude, letting you know when you can fly or letting
you know that you shouldn’t attempt to climb up a mountain!
It automatically adjusts your no-decompression time if you dive at
altitude and will also take into account the water temperature, so
that if you are doing a particularly cold dive it will either allow
you less no-decompression time or add to your decompression stop time.

Once you’re in decompression status, the Pro displays an ‘up’
arrow, which indicates the time required to reach the surface, including
stops, and the depth of the first stop. Once you begin your ascent,
you are warned if you exceed the computer’s ascent rate. Ascend
too quickly and the Pro takes this into account and extends your stop
time.

Your total ascent time and the duration
of each stage decompression stop is calculated assuming that you will
decompress at an exact depth of 3, 6, 9, 12 or 18m. Sometimes it is
preferable to stop a little deeper than the specified depth: it can
be more comfortable in a swell and allows a little leeway if you inadvertently
ascend a bit, giving you time to react before you ascend beyond the
safety limit and violate your stop. If necessary, the Pro will compensate
by adding more time to your required decompression stop. So when decompressing
below the necessary depth, make sure to monitor your air with even
more care than usual as your stop time may be longer.

As with all
of the current Uwatec computers, the Pro uses the Bühlmann
adaptive algorithm. This ‘smart algorithm’ is designed
to warn the diver of dive profiles that might increase the chance
of decompression illness. I wasn’t interested in pushing any
limits for the sake of a more complete review, and never incurred
any warnings from the Aladin other than to slow my ascent. The Aladin
Air typically required about a minute’s extra decompression
compared to the Pro for the same profiles. Compared to another model
we recently group tested, the Suunto Favor, decompression times
were two to three minutes longer.